Search

This qualitative study explores the experiences of Dalit students in one of the state universities of Uttar Pradesh in India. An Interpretative Phenomenological Analysis (IPA) was conducted to understand the experiences of Dalit students at higher education institutions, including caste-based prejudice and discrimination on campus. A total of seven themes emerged indicating caste-based prejudice and discrimination against Dalit students in both explicit and subtle ways at various levels of the university. Caste-based discrimination, humiliation, and exclusion were experienced by Dalit students at the level of fellow students, faculty, and administration.

Genograms have been an important tool for clinicians and therapists working with families; however, the use of genograms has not been extended beyond clinical settings. To address this gap in research, we developed qualitative genogram analysis (QGA), a three‐step protocol for analyzing transcribed interviews using family systems theory, representing family systems relational concepts visually in genograms, and identifying common patterns of family dynamics that emerged from these visualizations across families. We present the QGA protocol using interviews with family members who experienced elder family financial exploitation. This innovative use of genograms as part of an analytical process allows researchers to theorize family systems in innovative ways and go beyond examining each family relationship as a "variable" and look at relationship dynamics systemically and wholistically across families. [ABSTRACT FROM AUTHOR]

Homogenous charge compression ignition (HCCI) combustion can significantly reduce automotive pollution and increase the thermal efficiency of the engine. However, combustion phasing control is a major challenge in HCCI engines due to severe cyclic combustion variations. This study investigates the cyclic combustion dynamics of the HCCI engine using nonlinear dynamic methods such as return maps, recurrence plots (RPs), and recurrence quantitative analysis (RQA). Combustion stability and cyclic variations of HCCI combustion parameters were investigated on a modified four-stroke diesel engine. The experiments were conducted by varying relative air-fuel ratios (λ) and intake air temperatures ( T i ) at two engine speeds. In-cylinder pressure data of 2000 consecutive engine combustion cycles is logged for each test condition. In this study, deterministic characteristics of combustion phasing (CA50) and crank angle position of maximum cylinder pressure ( θ P max ) are investigated and compared by employing nonlinear dynamical methods. Return maps revealed that θ P max is having distinct and more frequently observed deterministic characteristics in comparison to CA50. Patterns in RPs showed a more persistent and sudden change in the combustion dynamics at higher engine speeds. Recurrence plot-based analysis found the existence of deterministic features in the combustion dynamics irrespective of the operating conditions. It was found using RQA parameters that the deterministic nature becomes stronger with a decrease in T i and any deviation in intermediate values of λ. Additionally, RQA measures advocate that CA50 has more deterministic characteristics at higher engine speed while θ P max at lower engine speed. Strong coupling and synchronization between θ P max and CA50 is indicated by cross-recurrence plots and CPR index when engine operated with a comparatively richer mixture. [ABSTRACT FROM AUTHOR]

A noisy nonlinear dynamical (NND) model available for cyclic variations in SI engines is examined using nonlinear time series methods. Heat release time series computed from this model is analyzed by employing bifurcation diagrams, return maps, recurrence plots, and recurrence quantitative analysis techniques. The analysis methodology is at first applied to a noisy Logistic map to optimize the necessary parameters, and later the same is used for the NND map. The presence of noise hides the local patterns of the dynamics and higher periodic orbits, making the bifurcation diagrams look fuzzy for both maps. An increase in the noise level and uncombusted residuals in the NND map advance the onset point of bifurcations toward a higher equivalence ratio. The application of the NND model is extended to represent the SI engine combustion dynamics for a higher amount of internal EGR as it is favored for cycle-resolved control due to its feedback period of one combustion cycle. The combined effect of lean charge and internal EGR leads to a more complex dynamical nature. The addition of a higher amount of internal EGR adds some complex chaotic-like regions in the bifurcation diagrams. For a low level of fluctuations in the NND map, more than four noisy periodic orbits are observed for such operating conditions. The geometry of phase space trajectories for the low-level noisy model data with a high level of internal EGR resembles a chaotic system. Bifurcation diagrams, recurrence plots, and quantitative recurrence analysis indicate an intermittent route to chaos at a highly lean and diluted charge. The presence of deterministic chaotic characteristics in combustion dynamics, along with effort-saving techniques of data acquisition and estimating combustion phasing, depicts the possibilities of practical application in active onboard control of engine systems. [ABSTRACT FROM AUTHOR]

Empathy and compassion are critical elements in counselling presence and practice. The present interpretive phenomenological study explored counsellor lived experiences of empathy and compassion. Through interpretative phenomenological analysis, findings highlighted how counsellors experience compassion and empathy, how boundaries shape wellness and practice with clients, and the impact of empathy and compassion over a career. The findings suggest that self‐other differentiation is key while using empathy to develop a strong therapeutic alliance and counsellor self‐care. Implications inform how counsellors can maintain wellness and learn to foster empathy and compassion in practice. [ABSTRACT FROM AUTHOR]

Alcohol fuels, primarily ethanol and methanol, have emerged as one of the important alternatives for sustainable transportation and power generation applications, due to the overall lower carbon dioxide (CO2) emissions. The higher octane number of alcohol makes it suitable for spark ignition (SI) engines while lower blend ratios can be used for compression ignition (CI) engines as well. Since significant work and exploration have already been performed for the application of alcohol in SI engines, the present study is primarily focused on alcohol utilization in CI engines. This review majorly consists of three parts: first, a discussion on the physical and chemical properties of ethanol and methanol from the fuel perspective, second, combustion, and engine performance of CI engines fueled with alcohol and lastly, emissions characterization of alcohol as fuel. A summary of this review is provided which highlights the potential of alcohol utilization in the form of blend or under dual-fuel combustion modes, as well as neat alcohol fueled CI engine. Alcohol-fueled CI engine improves the soot-NOx trade-off characteristic in comparison to conventional diesel combustion, this fuel could be an enabler to meet future emissions regulations. Overall lower CO2 emissions (up to 15% lower compared to diesel) by utilizing alcohol as fuel make it suitable for sustainable transportation. [ABSTRACT FROM AUTHOR]

This work investigates the influence of fuel injection events on the nanoparticle emission characteristics of light-duty gasoline-diesel RCCI engine. The formation of nanoparticle emissions strongly depends on fuel injection events. The present study experimentally investigates the influence of diesel injection pressure, injection timing, and port-injected gasoline mass on the nanoparticles emitted from the gasoline-diesel RCCI engine. For this purpose, the engine is tested at different engine speeds and a fixed load of 1.5 bar BMEP without exhaust gas recirculation. The particle-size and number distribution (PSD) and total particle number (total PN) concentration are measured using a differential mobility spectrometer. The results depict that at higher diesel injection pressure (IP) operation, the peak of the NMP increases while the AMP peak decreases for neat diesel operation as well as RCCI engine. Nucleation, as well as accumulation mode particles, increases with advanced diesel injection timing in RCCI combustion. An increase in port fuel injected mass also leads to an increase in the total particle concentration and total unburned hydrocarbon (THC) emissions. [ABSTRACT FROM AUTHOR]

In this article, we explore potential benefits of yoga, an ancient Indian tradition for spiritual growth and development, for counselors. Counselors use themselves as instruments to support clients and are constantly exposed to the traumatic experiences of clients, which may leave them susceptible to secondary traumatic stress or compassion fatigue (Shallcross, 2011). Yoga can help counselors not only in achieving holistic wellness but also in developing a way of being consistent with the characteristics of an effective counselor. Furthermore, yoga, as a spiritual practice, can empower counselors to embark on a spiritual journey driven by their own personal experiences. [ABSTRACT FROM AUTHOR]

Investigating how counselors perceive technology as a tool for delivering counseling services is crucial to understand the usage and challenges that may have implications for training programs, policymaking, and allocation of resources. With the COVID-19 crisis and accompanying shelter-in-place and self-distancing guidelines, telemental health, including distance counseling, has become a satisfactory primary delivery system and is now expected to be part of routine counseling care. The present pre-COVID-19 study explored practicing counselors' perceptions of distance counseling regarding advantages and challenges. While noting benefits, results indicate continuing barriers to widespread telemental health use encompassing licensure, training, safety, privacy, evaluation, and regulatory policies. Also, attention is needed for therapeutic relationships and culturally alert digital interventions. In addition, counselors can take advantage of rapidly changing technologies to provide numerous innovative counseling services. [ABSTRACT FROM AUTHOR]

A novel circularly polarized hexagonal ring microstrip patch antenna with asymmetrical feed is proposed for S, C, and X‐band applications. A semi‐arc‐shaped slot is integrated into the ground plane, and the hexagonal ring is tilted by an angle of 25° with respect to the microstrip‐line feed (asymmetric), which creates a circularly polarized UWB. The simulation of the proposed antenna is carried out using Ansoft HFSS v.13 and the measurement is done with an N5230A vector network analyzer. The simulated and the measured results of our proposed antenna are in good agreement. The successful implementation of the asymmetrical feed shows a broader impedance bandwidth of 134% (B.W = 9.55 GHz) from 2.34 to 11.89 GHz at 7.12 GHz of the center frequency. The 3‐dB axial ratio B.W is 2.8% (7.1‐7.3 GHz) and 21.8% (9.8‐12.2 GHz) in the UWB range. The average gain of the proposed antenna is 4.15 dBi. Good RHCP waves are also found in the x‐z and y‐z planes. The proposed antenna can be effectively used in S, C, and X‐band applications. [ABSTRACT FROM AUTHOR]

This qualitative study explores the experiences of Dalit students in one of the state universities of Uttar Pradesh in India. An Interpretative Phenomenological Analysis (IPA) was conducted to understand the experiences of Dalit students at higher education institutions, including castebased prejudice and discrimination on campus. A total of seven themes emerged indicating caste-based prejudice and discrimination against Dalit students in both explicit and subtle ways at various levels of the university. Caste-based discrimination, humiliation, and exclusion were experienced by Dalit students at the level of fellow students, faculty, and administration. [ABSTRACT FROM AUTHOR]

Hydrogen is a clean potential alternative fuel for internal combustion engines and completely eliminates the carbon based engine emissions (CO, CO 2 and unburned hydrocarbons). Homogenous charge compression ignition (HCCI) is a low temperature combustion mode with higher thermal efficiency and ultralow NO x emission. Hydrogen HCCI engine can combine potential benefit of fuel and combustion characteristics. In HCCI engine, combustion is governed by the chemical kinetics of the oxidation reactions. In-order to find a suitable reaction mechanism to numerically predict the combustion characteristics of hydrogen HCCI engine, 15 recent hydrogen combustion mechanisms are compared and analyzed. All mechanisms were simulated using a stochastic reactor model (SRM) to evaluate the combustion parameters for HCCI engine. Simulations were performed by varying inlet temperature (400–440 K), intake pressure (1.0–3.0 bar), engine speed (1000–3000 rpm) and relative air-fuel ratio (λ = 2 to 8) for all the mechanisms. Ignition delay predicted from different mechanism was compared with experimental data and ignition delay was also compared at engine like condition using all the test mechanisms. Error in prediction of different combustion parameters such as start of combustion (CA 10 ), maximum cylinder pressure (P max ) and maximum heat release rate (HRR max ) were evaluated using different hydrogen combustion mechanisms. It was found that a recently developed hydrogen mechanism (Maurya-2017) shows the closet resemblance with the experimental cylinder pressure data. The Oconaire-2004 mechanism was able to accurately predict the characteristics of hydrogen HCCI combustion. It was also found that NUIG-NGM-2010 and CRECK-2014 mechanisms were able to estimate the HCCI combustion characteristics under higher combustion temperature. [ABSTRACT FROM AUTHOR]

Analysis of measured in-cylinder pressure data provides various parameters that characterize engine combustion process. Advanced engine control technologies use cylinder pressure based combustion parameters for closed loop control. Four step signal processing (i) absolute pressure correction, (ii) crank angle position referencing, (iii) cycle averaging and (iv) filtering is typically applied to get sufficiently accurate cylinder pressure data for an engine cycle. This paper focuses on cycle averaging and filtering of in-cylinder pressure signal from a conventional compression ignition (CI) engine. Experiments are conducted at different engine load and compression ratios at 1500 rpm. The in-cylinder pressure trace of 2500 consecutive engine cycles is recorded and analyzed. Effect of in-cylinder pressure signal noise and cyclic variation on combustion analysis is investigated. A method based on standard deviation of pressure and pressure rise rate is used to find sufficient minimum number of engine cycles to be recorded for averaging to get reasonably accurate pressure data independent of cyclic variability. [ABSTRACT FROM AUTHOR]

Internal combustion engine research on alternative fuels has gained momentum because of growing awareness about energy security and environmental issues worldwide. Biodiesel offers an ideal solution to these problems and is an excellent partial replacement to mineral diesel. In this study, Karanja biodiesel blended with mineral diesel has been investigated for macroscopic spray characterization vis-à-vis baseline mineral diesel by varying fuel injection pressures (50, 100 and 150 MPa). Spray developed with relatively narrower spray angle for KB20. Injector needle movement for energizing and real injection durations were also compared for diesel and KB20 at fuel injection pressures of 50, 100 and 150 MPa. Needle movement was slightly higher for KB20 because of its relatively higher viscosity. However, with increasing fuel injection pressure, the difference reduced and showed quite similar results. A 2.2 L common rail direct injection sport utility vehicle EURO-IV diesel engine was used for the experiments. Engine performance, emissions and combustion characteristics of KB20 were compared with baseline mineral diesel at (1) the rated engine speed (2500 r/min) with varying engine loads as well as (2) at the rated load at varying engine speeds (1500–3500 r/min). Brake thermal efficiency of KB20 was lower than mineral diesel. Brake-specific carbon monoxide and carbon dioxide emissions decreased with increasing brake mean effective pressure and showed increasing trend with increasing engine speeds. KB20 showed emission of higher number of particles compared to mineral diesel at all engine operating conditions. Higher oxygen content of biodiesel resulted in shorter ignition delay and slightly higher peak cylinder pressure. KB20 showed relatively longer combustion duration compared to mineral diesel at 2500 r/min engine speed. [ABSTRACT FROM AUTHOR]

Biofuels are attracting global attention as alternate transportation fuels due to advantages of their being produced from locally available renewable resources, lower pollution potential, and biodegradable nature. Butanol is fast emerging as one of the competitive biofuels for use in transportation engines. Homogeneous charge compression ignition (HCCI) engines have shown great potential for higher engine efficiency and ultralow NOx and particulate matter (PM) emissions. This experimental study is therefore carried out to combine the advantages of biofuels and HCCI engines, both. Detailed performance, combustion, and emission characteristics of n-butanol fueled HCCI engine are investigated experimentally. The study is conducted on a four cylinder diesel engine, whose one cylinder was modified to operate in HCCI combustion mode. Port fuel injection technique was used for homogeneous charge preparation in the intake manifold. Auto-ignition of fuel in the engine cylinder was achieved by intake air preheating. In-cylinder pressure-crank angle data acquisition with subsequent heat release analyses and exhaust emission measurements were done for combustion and emission characterization. In this paper, the effect of intake air temperature and air-fuel ratio on the combustion parameters, thermal and combustion efficiency, ringing intensity (RI), and emissions from n-butanol fueled HCCI engine were analyzed and discussed comprehensively. Empirical correlations were derived to fit the experimental data for various combustion parameters. [ABSTRACT FROM AUTHOR]

Alcohols (ethanol and methanol) are being widely considered as alternative fuels for automotive applications. At the same time, homogeneous charge compression ignition (HCCI) engine has attracted global attention due to its potential of providing high engine efficiency and ultralow exhaust emissions. Environmental legislation is becoming increasingly stringent, sharply focusing on particulate matter (PM) emissions. Recent emission norms consider limiting PM number concentrations in addition to PM mass. Therefore, present study is conducted to experimentally investigate the effects of engine operating parameters on the PM size-number distribution in a HCCI engine fueled with gasoline, ethanol, and methanol. The experiments were conducted on a modified four-cylinder diesel engine, with one cylinder modified to operate in HCCI mode. Port fuel injection was used for preparing homogeneous charge in the HCCI cylinder. Intake air preheating was used to enable auto-ignition of fuel-air mixture. Engine exhaust particle sizer (EEPS) was used for measuring size-number distribution of soot particles emitted by the HCCI engine cylinder under varying engine operating conditions. Experiments were conducted at 1200 and 2400 rpm by varying intake air temperature and air-fuel ratio for gasoline, ethanol, and methanol. In this paper, the effect of engine operating parameters on PM size-number distribution, count mean diameter (CMD), and total PM numbers is investigated. The experimental data show that the PM number emissions from gasoline, ethanol, and methanol in HCCI cannot be neglected and particle numbers increase for relatively richer mixtures and higher intake air temperatures. [ABSTRACT FROM AUTHOR]

Homogeneous charge compression ignition (HCCI) engines have potential to provide both diesel like efficiencies and very low NOx and particulate matter (PM) emissions. There is growing global interest in using alternative biofuels in order to reduce the reliance on conventional fossil fuels. Therefore this experimental study was carried out to investigate performance, combustion and emission characteristics of HCCI engine fueled with ethanol and methanol and compare it with baseline gasoline fuel. The experiments were conducted on a modified four-cylinder four-stroke engine at different engine speeds using port fuel injection technique for preparing homogeneous charge. To achieve auto-ignition of air-fuel mixture in the combustion chamber, intake air pre-heater was used. In-cylinder pressure data acquisition with subsequent heat release analysis and exhaust emission measurements were done for combustion and emission diagnostics. In this paper, effect of intake air temperature and air-fuel ratio on combustion parameters, thermal efficiency, combustion efficiency, ringing intensity and emissions in HCCI engine is analyzed and discussed. Results show that methanol and ethanol are good replacements to gasoline in HCCI combustion mode. [ABSTRACT FROM AUTHOR]

Background In recent years, it has been well documented that gut flora not only influence mosquito physiology, but also significantly alter vector competency. Although, salivary gland and gut constitute key partners of the digestive system, it is still believed that salivary glands may harbor less flora than gut (Parasit Vectors 6: 146, 2013). Methods Using a metagenomic approach, we have identified for the first time the diverse microbial community associated with these two physiologically different tissues of the digestive system in the mosquito Anopheles culicifacies. Results A total of 17 different phyla could be assigned to the whole metagenomic dataset, predominated by the phylum Proteobacteria, Firmicutes, Bacteriodetes, Tenericutes and Actinomycetes. Common bacteria included the members of Enhydrobacter, Agromonas, Serratia, Ralsonia, Lactobacillus, Pseudomonas, Streptococcus, Rubrobacter, Anaerococcus, Methylobacterium, Turicibacter, Elizabethkingia etc. in both the tissues representing 'core microbiota' of the mosquito digestive system. Salivary associated unique bacterial community included the members of Chloriflexi, Chlorobi, Cyanobacteria, Nitrospira, TM7, Armatimonadetes, Planctomycetes, Fibrobacteres etc. Conclusion We find that the salivary gland microbial community structure is more diverse than gut of the mosquito, probably due to differential feeding associated engagements such as food acquisition, ingestion and digestion processes. [ABSTRACT FROM AUTHOR]

Abstract: Combustion instability and cyclic variations lead to the requirement of closed loop control for use of homogeneous charge compression ignition (HCCI) engine technology for automotive applications. The closed loop control of HCCI combustion requires robust combustion timing parameters with a systematic and detailed study of its variations vis-à-vis engine operating conditions. An experimental study is conducted to provide insight into cyclic variations of HCCI combustion phasing for two fuels (gasoline and methanol) using statistical techniques. In this study, cycle-to-cycle variations of heat release parameters such as Maximum Rate of Heat Release (ROHRmax), 10% Mass Burn Fraction (MBF), 50% MBF, 90% MBF and Indicated Mean Effective Pressure (IMEP) of HCCI combustion engine fueled with methanol and gasoline were investigated using a modified two-cylinder, four-stroke engine. The experiments were conducted with different engine operating conditions at constant intake air temperature (140°C) and different air–fuel ratios at constant engine speed (1500rpm). To evaluate the cycle-to-cycle variations of combustion parameters at different test conditions, coefficient of variation (COV) and standard deviation of parameters were used. The results showed that CA50 (crank angle position of 50% MBF) is a robust parameter for the closed loop control of HCCI combustion. [Copyright &y& Elsevier]

Abstract: The homogeneous charge compression ignition (HCCI) is an alternative combustion concept for in reciprocating engines. The HCCI combustion engine offers significant benefits in terms of its high efficiency and ultra low emissions. In this investigation, port injection technique is used for preparing homogeneous charge. The combustion and emission characteristics of a HCCI engine fuelled with ethanol were investigated on a modified two-cylinder, four-stroke engine. The experiment is conducted with varying intake air temperature (120–150°C) and at different air–fuel ratios, for which stable HCCI combustion is achieved. In-cylinder pressure, heat release analysis and exhaust emission measurements were employed for combustion diagnostics. In this study, effect of intake air temperature on combustion parameters, thermal efficiency, combustion efficiency and emissions in HCCI combustion engine is analyzed and discussed in detail. The experimental results indicate that the air–fuel ratio and intake air temperature have significant effect on the maximum in-cylinder pressure and its position, gas exchange efficiency, thermal efficiency, combustion efficiency, maximum rate of pressure rise and the heat release rate. Results show that for all stable operation points, NO x emissions are lower than 10ppm however HC and CO emissions are higher. [Copyright &y& Elsevier]

Abstract: Combustion in HCCI engines is a controlled auto ignition of well-mixed fuel, air and residual gas. Since onset of HCCI combustion depends on the auto ignition of fuel/air mixture, there is no direct control on the start of combustion process. Therefore, HCCI combustion becomes unstable rather easily, especially at lower and higher engine loads. In this study, cycle-to-cycle variations of a HCCI combustion engine fuelled with ethanol were investigated on a modified two-cylinder engine. Port injection technique is used for preparing homogeneous charge for HCCI combustion. The experiments were conducted at varying intake air temperatures and air–fuel ratios at constant engine speed of 1500rpm and P-θ diagram of 100 consecutive combustion cycles for each test conditions at steady state operation were recorded. Consequently, cycle-to-cycle variations of the main combustion parameters and performance parameters were analyzed. To evaluate the cycle-to-cycle variations of HCCI combustion parameters, coefficient of variation (COV) of every parameter were calculated for every engine operating condition. The critical optimum parameters that can be used to define HCCI operating ranges are ‘maximum rate of pressure rise’ and ‘COV of indicated mean effective pressure (IMEP)’. [ABSTRACT FROM AUTHOR]